1. Field of the Invention
The present invention relates to a scanning system comprising of a scanner and an image acquisition controller and a method for interactively improving the quality of scanned document images in real-time.
2. Discussion of the Background
In recent times, scanners have become very popular in both the consumer sector and the commercial sector. Scanners are typically connected to an image acquisition controller. After scanning in a document, the scanned image is displayed on the image acquisition controller monitor. The document can be a text document, a graphic document, or a photographic document.
There are many applications for the use of a scanner. One application is for archiving documents. Instead of maintaining paper documents, one can simply scan in the documents and archive the image files on computer storage media, such as hard drives, compact discs, tape drives, or DVDs. Another application is for the storage of photographs. Instead of maintaining photo albums, the photographic images are stored in a computer storage media. The photographic images can be retrieved anytime and can be printed to a printer connected to the image acquisition controller. There are numerous scanner applications. However, this invention deals with the enhancement of the scanned image and not the applications of a scanner.
A modern scanner system consists of a scanner and an image acquisition controller as shown in FIG. 1. The scanner will typically be comprised of an apparatus for receiving documents to be scanned and a scanner card for placing in an expansion slot of an image acquisition controller. The apparatus for receiving documents to be scanned can be of a flat-bed type or a drum type of apparatus. The scanner card will contain imaging processing hardware. Typically, the imaging processing hardware will be comprised of: a charged couple device, a normalization processor, an image processor, and an image cache. The image cache may or may not reside on the scanner card. If it does not reside on the scanner card, then it may reside on the image acquisition controller or utilize the image acquisition controller""s memory as an image cache. FIG. 2 depicts a design in which the image cache is resident on the scanner card. FIG. 3 depicts a possible design in which the image cache is not resident on the scanner card.
FIG. 4 depicts an image control settings displayed on an image display or a computer monitor that can be adjusted on the image acquisition controller.
The common image control setting is a static type of system and does not employ a real-time closed feedback loop between the scanner, the scanner card, and the image acquisition controller. FIG. 5 shows a typical system without a real-time closed feedback loop. The shortfall of a scanner system without a real-time closed feedback loop is that when a user is not satisfied with the scanned image, the user must adjust the image control settings and rescan the document. Depending on the throughput of a scanner and the design of the scanner control setting, the adjustment and the rescanning processes may be time consuming and laborious. FIGS. 2 and 3 show a system having a real-time closed feedback loop.
An objective of the invention is to significantly reduce the burden of necessity for the rescanning of documents if the scanned images are found unsatisfactory.
The present invention for accomplishing the above objective consists in a method for a scanner system having a scanner and an image acquisition controller having a display terminal, characterized by the steps of scanning documents, storing the image data in a fast retrieval memory or an image cache, loading that image data into an image processor and processing the data in the image processor to allow a user to find an optimal setting to enhance the image. If the processed image data is unsatisfactory, the data in the image cache can be reloaded into the image processor to reprocess the image data. This step will be repeated until the user finds the processed image data satisfactory.
The image processing and reprocessing operations are performed in hardware. Thus, they can be done fast enough to give an almost instantaneous result of the processing or reprocessing.